Develop device to increase exercise walking in patients with knee, hip, balance or other problems. Exercise walking has been shown to have significant health benefits. However, many older adults avoid walking due to pain, fear from falls or other problems. Device based on prototypes developed for running. Like crutches, they allow the entire body weight to be supported by the poles. Like canes, they are comfortable to use for extended periods. In Phase 1 we conducted initial trials of the exercise poles with healthy elderly adults, to access the kinematics, changes in stability and impact on well being. We also developed questionnaires and improved prototypes. In Phase 2 we will conduct a 2 year longitudinal study using a group of 200 subjects age 65-85 who are non-exercisers. Testing refined prototypes against a control group and existing crutch, cane and walker designs, we will determine effectiveness for different elderly populations, optimize the design, and create the required educational materials for health care professionals. We expect this device will increase elderly exercise walking rates and have a measurable impact on the users overall health, sense of well being, mastery of their environment and instrumental activities of daily living. PROPOSED COMMERCIAL APPLICATIONS: Over 16 million Americans over 65 do not exercise, despite significant health benefits. Walking is perhaps the most highly regarded exercise by both health professionals and the elderly. A significant number of elderly likely avoid walking due to pain or fear of falling. By creating an assistive device significantly more comfortable and better looking than standard crutches, we foresee a market of 2.5 million seniors. This is a $40-100 million dollar a year market.